The airplane was partially destroyed an the Airline Transport pilot fatally injured on colliding with trees and the ground while maneuvering at 1820 Eastern time. Visual conditions prevailed. One passenger received serious injuries. One witness observed the airplane take off and climb to about 500 feet. He then observed the airplane make a steep left 90-degree bank back towards the runway, in a slight nose-down attitude. The witness could not hear the engine. The witness stated the airplane appeared to be mushing/dropping down in a flat slight nose down attitude until it disappeared from view. Two other witnesses stated the engine sounded like it was shutting down and quit. They then heard a sound like the pilot was attempting to restart the engine.